Organosilicon compounds are important starting materials for organosilicon polymers. Especially, sulfur atom containing organosilicon compounds are interesting and potential monomer precursors in synthesizing functional inorganic polymers. In 1975, Voronkov and co-workers reported that sodium alkylthiolate reacted with haloalkylalkoxysilane to give the corresponding alkylthio-substituted products through the C—S coupling reaction, eliminating sodium halide [Voronkov, M. G.; Sorokin, M. S.; D'yakov, V. M.; Sigalov, M. V. Zhurnal Obshchei Khimii, 1975, 45 (8), 1807–11]. Here, 1,1,1-trimethoxy-3-thio-1-silabutane was synthesized by the reaction of methyl iodide with sodium trimethylsilylmethylthiolate [NaSCH2Si(OMe)3].
In 2001, Sorokin; Voronkov reported that a sulfur atom-containing alkylalkoxysilane could be prepared by a Si—C coupling reaction of haloalkylalkoxysilane with RSMgX in tetrahydrofuran in situ [Sorokin, M. S.; Voronkov, M. G. Russian Journal of General Chemistry, 2001, 71 (12), 1883–90].
As explained above, the current known methods for preparing sulfur atom-containing organosilanes are limitedly synthesizing alkoxysilanes by S—C coupling of haloalkylalkoxysilane with organometal reagents. However, these methods are not applied for chlorosilane compounds containing Si—Cl bond(s), which can be modified by alcohol, amine, organometal reagents, etc. and haloalkylalkoxysilane should be prepared by two step reactions: hydrosilylation and methoxylations. The former reaction requires a very expensive platinum catalyst and the latter evolves HCl gas in the reaction of Si—Cl with methanol and thus needs a trapping process of HCl.
The inventors have obtained a patent on a method of preparing a variety of organosilicon compounds by the dehydrohalogenation of alkyl halide and chlorosilane in the presence of the tertiary phosphine [U.S. Pat. No. 6,251,057, Korean Patent No. 306574].

The inventors also prepared organosilicon compounds with Si—Cl bonds from the Si—C coupling reaction of chloromethyl-substituted organosiliocn compounds with chlorosilane containing Si—H bond in better yield using tetraalkylphosphonium salt catalyst instead of tertiary phosphine or amine compound. This tetraalkylphosphonium salt catalyzed reaction provide a better yield compared with phosphine compound-catalyzed reaction, because the catalyst can be separated from the reaction mixture and recycled easily [Jung, I.; Yoo, B.; Han, J.; Kang, S. U.S. Pat. No. 6,392,077].
However, a Si—C coupling reaction of hydrochlorosilane containing Si—H bond with organothiomthyl halide in the presence of organic amine, phosphine, or organic salt have never been reported